✨ feat(manga,device): 漫画免签名兜底与 phone 注册身份选项

- /manga 设备池签名路线全部失败时自动降级 wkbrowser 免签名路线（materials/skeleton 三段策略收集原图直链，无需设备/签名/解密），响应附 source: wkbrowser
- 新增配置 fanqie.device_identity（默认 pad 保持现状；phone 对齐书源真机注册 payload：host_bit 64 + 补 hardware/device_device/fingerprint 字段）
- README 与 openapi.yaml 同步文档，新增 manga_fallback 解析测试

internal/fqapi/device_register.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fanqie/internal/common"
+	"fanqie/internal/config"
 	"fmt"
 	"math/big"
 	"net"
@@ -186,6 +187,22 @@ func generateIPv6List() []map[string]string {
 	}
 }
 
+// deviceIdentity 注册设备身份：pad（默认，历史行为）/ phone（对齐手机 App 书源注册 payload）
+func deviceIdentity() string {
+	if cfg := config.GetConfig(); cfg != nil && cfg.Fanqie.DeviceIdentity == "phone" {
+		return "phone"
+	}
+	return "pad"
+}
+
+// deviceCustomFields 注册身份对应的 custom 字段
+func deviceCustomFields() map[string]interface{} {
+	if deviceIdentity() == "phone" {
+		return map[string]interface{}{"host_bit": 64, "dragon_device_type": "phone"}
+	}
+	return map[string]interface{}{"host_bit": 32, "dragon_device_type": "pad"}
+}
+
 // GenerateFullRequestBody 生成完整的请求体数据
 func GenerateFullRequestBody() map[string]interface{} {
 	rawData := map[string]interface{}{
@@ -214,7 +231,7 @@ func GenerateFullRequestBody() map[string]interface{} {
 			"sim_serial_number":     []interface{}{},
 			"oaid_may_support":      false,
 			"device_platform":       "android",
-			"custom":                map[string]interface{}{"host_bit": 32, "dragon_device_type": "pad"},
+			"custom":                deviceCustomFields(),
 			"pre_installed_channel": "",
 			"is_system_app":         0,
 			"sdk_flavor":            "china",
@@ -234,6 +251,16 @@ func GenerateFullRequestBody() map[string]interface{} {
 	}
 	header["ipv6_list"] = generateIPv6List()
 
+	// phone 身份补充真机指纹字段（对齐书源注册 payload，规避 pad 身份的差异化风控）
+	if deviceIdentity() == "phone" {
+		rom, _ := header["rom"].(string)
+		header["hardware"] = "qcom"
+		header["device_device"] = rom
+		header["fingerprint"] = fmt.Sprintf("%v/%v/%v:%v/%s/%s:user/release-keys",
+			header["device_brand"], header["device_model"], header["device_model"],
+			header["os_version"], rom, rom)
+	}
+
 	for k, v := range genTime {
 		rawData[k] = v
 	}